| Autor: |
Yun Hsin Wang, Sheng Feng Weng, Chi-Shen Lee |
| Rok vydání: |
2013 |
| Předmět: |
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| Zdroj: |
Applied Catalysis B: Environmental. :359-366 |
| ISSN: |
0926-3373 |
| DOI: |
10.1016/j.apcatb.2013.01.025 |
| Popis: |
Pyrochlore phases solid solutions, La 2 Ce 2− x Ru x O 7 ( x = 0–0.35) were prepared with a sol–gel process and used as catalysts for the autothermal steam reforming of ethanol. The samples as prepared were characterized with powder X-ray diffraction (PXRD), X-ray photoelectron spectra (XPS), and temperature-programmed reduction (TPR). The XPS and TPR spectra revealed the effect of doped Ru n + to oxidation states of La and Ce sites. The low temperature reduction ability and relative concentration of Ce 4+ ions are increased as the cell-dimension decreased. Tests of catalytic activity showed that the reforming performance of La 2 Ce 2− x Ru x O 7 catalysts was affected by the Ru/Ce loading ratio. For all catalysts, partial oxidation was favored at a large C/O composition; incomplete ethanol conversion was observed for C/O ≥ 0.7. The optimized catalyst was La 2 Ce 1.8 Ru 0.2 O 7 with hydrogen production rate ( r H 2 ) 2.01 × 10 −3 mol s −1 g cat −1 (autothermal temperature ∼600 °C and 97% ethanol conversion at C/O = 0.6). The catalyst exhibited stable r H 2 over 26 h of the reaction with ethanol conversion >95%. r H 2 of the catalyst gradually decreased thereafter because LaAlO 3 started to formed and affected catalytic process. For the catalyst, the Ru ions remained well dispersed before and after the AESR reaction. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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